Said fund shall be expended for the purposes in this chapter provided. Any county, for the control of waters subject to flood conditions from streams, tidal or other bodies of water affecting such county, may inside or outside the boundaries of such county, construct, operate and maintain dams and impounding basins and dikes, levees, revetments, bulkheads, rip-rap or other protection; may remove bars, logs, snags and debris from and clear, deepen, widen, straighten, change, relocate or otherwise improve and maintain stream channels, main or overflow; may acquire any real or personal property or rights and interest therein for the prosecution of such works or to preserve any floodplain or regular or intermittent stream channels from any interference to the free or natural flow of flood or stormwater; and may construct, operate and maintain any and all other works, structures and improvements necessary for such control; and for any such purpose may purchase, condemn or otherwise acquire land, property or rights, including beds of nonnavigable waters and state, county and school lands and property and may damage any land or other property for any such purpose, and may condemn land and other property and rights and interests therein and damage the same for any other public use after just compensation having been first made or paid into court for the owner in the manner prescribed in this chapter. The purposes in this chapter specified are hereby declared to be county purposes.